SSH tunnel setup

Initialise Kerberos credentials kinit mycernusername@CERN.CH

Edit/Create your $HOME/.ssh/config and add the following

Host lxtunnel
        HostName lxplus.cern.ch
        User mycernusername
        Protocol 2
        ForwardX11 no
        PasswordAuthentication no
        LocalForward 22000 np04-srv-013.cern.ch:22
        LocalForward 22001 np04-srv-013.cern.ch:5901
        LocalForward 22002 np04-srv-013.cern.ch:5902
        LocalForward 22003 np04-srv-013.cern.ch:5903
        LocalForward 22004 np04-srv-013.cern.ch:5904
        LocalForward 22005 np04-srv-013.cern.ch:5905
        LocalForward 22006 np04-srv-013.cern.ch:5906
        LocalForward 22007 np04-srv-013.cern.ch:5907
        LocalForward 22008 np04-srv-013.cern.ch:5908
        LocalForward 22009 np04-srv-013.cern.ch:5909

Host np13
        Hostname localhost
        Port 22000
        User mycernusername

Add some aliases to your .bashrc

alias lxtun="ssh -N -C -f -q lxtunnel ; sleep 1 ; [[ \$(ps auxwww | grep lxtunnel | grep -c -v grep) == 1 ]] && echo ok || echo not ok"
alias lxtunkill="for i in \`ps auxww | grep lxtunnel | grep -v grep | awk '{print \$2}'\`; do echo killing \$i; kill \$i; done"

Try the tunnel

source .bashrc
lxtun

Try connect to np04-srv-013

 
ssh np13

VNC setup

ssh to np04-srv-013 and set a VNC password.

ssh np13
vncpasswd

Create/Replace the file $HOME/.vnc/xstartup with the following

#!/bin/sh

unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
#exec /etc/X11/xinit/xinitrc
exec xfce4-session

chmod u+x xstartup

Start the VNC server and note the desktop number - e.g. ":1"

 
vncserver 

Connect via your favourite VNC client with the details Host = localhost Port = 22001 ... 22009 (last digit matches desktop number)

To kill vncserver

ssh np13
vncserver -kill :1

-- KarolH - 2017-09-26